Variable speed drive

ABSTRACT

A variable speed drive has a driving wheel and a driven wheel disposed at right angles to each other, with the circumferential edge of one of the wheels engaging the side surface of the other wheel. Either wheel may function as the driving wheel; the other then functions as the driven wheel. To change the speed and/or direction of rotation, the position of one of the wheels is changed relative to the other, without disturbing the right-angle relationship, by moving the axis of rotation of one of the wheels along the diametral plane of the other wheel. The circumferential edge of said one wheel is provided with a series of spaced-apart circular discs portions of which protrude radially from the circumferential edge of the wheel. Each of the discs is mounted for rotation on its own axis, the axis of rotation being tangential, or substantially tangential, to the wheel. The projecting discs engage, or are engaged by, the side surface of the other wheel. When the speed and/or direction of rotation is to be changed by changing the relative positions of the two wheels, the projecting discs which are in engagement with the side surface of the other wheel merely roll on the side surface.

United States Patent Faraghan [451 July 4,1972

[54] VARIABLE SPEED DRIVE Joseph T. Faraghan, 600 Arthur Street,Philadelphia, Pa. 19111 221 Filed: J8IL6, 1971 21 Appl.No.: 104,361

[72] Inventor:

Primary Examiner-Leonard H. Gerin Auomey-Paul & Paul [57] ABSTRACT Avariable speed drive has a driving wheel and a driven wheel disposed atright angles to each other, with the circumferential edge of one of thewheels engaging the side surface of the other wheel. Either wheel mayfunction as the driving wheel; the other then functions as the drivenwheel. To change the speed and/or direction of rotation, the position ofone of the wheels is changed relative to the other, without disturbingthe right-angle relationship, by moving the axis of rotation of one ofthe wheels along the diametral plane of the other wheel. Thecircumferential edge of said one wheel is provided with a series ofspaced-apart circular discs portions of which protrude radially from thecircumferential edge of the wheel. Each of the discs is mounted forrotation on its own axis, the axis of rotation being tangential, orsubstantially tangential, to the wheel. The projecting discs engage, orare engaged by, the side surface of the other wheel. When the speedand/or direction of rotation is to be changed by changing the relativepositions of the two wheels, the projecting discs which are inengagement with the side surface of the other wheel merely roll on theside surface.

2 Claims, 4 Drawing Figures e/kgl PKTENTEDJIJL 4 m2 3 6 73 8 8 O Fig.4

INVENTOR.

Joseph T. Furughon ATTORNEYS.

VARIABLE SPEED nruvr:

BACKGROUND OF THE INVENTION Variable speed drives are known wherein thedriving and driven wheels are disposed at right angles to each otherwith the circumferential edge of one wheel in frictional engagement withthe side surface of the other. In such variable speed drives, the speedand/or direction of rotation are changed by moving the position of onewheel relative to the other along the diameter thereof. When this isdone in prior art devices, unless the two wheels are disengaged fromeach other, the peripheral edge of the one wheel is dragged across theside face of the other, with considerable frictional resistance beingdeveloped, and with resultant wear on the wheels.

SUMMARY OF THE INVENTION A principal object of the present invention isto provide a variable speed drive of the type referred to above but inwhich the speed and/or direction of rotation may be changed withoutdisengaging the two wheels and without dragging the circumferential edgeof the one wheel across the side surface of the other.

A more specific object is to provide a variable speed drive of theforegoing type in which, when the speed and/or direction of rotation isto be changed, the peripheral edge of the one wheel is moved across theflat face of the other wheel by a rolling engagement, rather than africtional or dragging engagement, thereby to avoid wear and tear.

These and other objects are accomplished by providing around acircumferential edge of the one wheel which is adapted to engage theside surface of the other, a series of spaced-apart circular discs,radially disposed. A portion of each disc projects radially beyond theperiphery of the wheel on which it is mounted. Each of the discs ismounted to be rotatable on its own axis, each axis of rotation beingtangential, or substantially tangential, to the supporting wheel. As thewheel rotates, the projecting discs engage the side surface of the otherwheel, and either drive the other wheel or are driven by the otherwheel, according to which of the two wheels is employed as the drivingwheel. As previously indicated, either of the two wheels may function asthe driving wheel, the other then functioning as the driven wheel.

When the relative positions of the two wheels is to be changed to changethe speed and/or direction of rotation of the drive, the projectingdiscs which are in engagement with the side surface of the one wheelmerely roll on the side surface thereof. There is no frictional dragduring the change in speed, and the wear on the wheels is substantiallyreduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view, partly insection, of a simplified construction embodying the present invention;

FIG. 2 is an elevational view looking along the line 2--2 of FIG. 1;

FIG. 3 is a view looking along the line 3-3 of FIG. 2;

FIG. 4 is a view looking along the line 44 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan viewshowing a first wheel and a second wheel 20 mounted at right anglesrelative to each other. Wheel 10 is mounted on a horizontal shaft 12,and wheel 20 is mounted on a shaft 22 which is also horizontallydisposed but which extends at right angles to shaft 12. Each of thewheels 10 and 20 are secured to their respective shafts, as by keys.

So far as the present invention is concerned, any suitable mechanism maybe provided for changing the relative positions of wheels 10 and 20. InFIG. 1, the position of wheel'20 is indicated as being movable to thepositions P1 and P2 shown in phantom, and simplified means foraccomplishing such movement are illustrated. It is to be understood,however, that the particular means shown for mounting wheel 20 and forchanging its position relative to wheel 10 are merely illustrative andthat other means could be employed for this purpose.

In FIG. 1, shaft 22 is shown supported in a bearing 23 in a frame 24.The right end of shaft 22 is provided with a bore 25 of square crosssection which receive a projection 26 of corresponding square crosssection which extends forwardly from a shaft 27 which is supported forrotation in a frame member, not shown.

Pivotally supported in frame 24 are a pair of lever arms 31, one on eachside of shaft 22, only one being visible in FIG. 1. Each of the arms 31is provided with a pin 32 which project inwardly toward the shaft 22 andare received in slots formed on each side of shaft 22 by a pair ofspaced-part vertical members 33 and 34 which are fixed on shaft 22 andextend outwardly to either side thereof.

To move the wheel 20 from the position shown in solid lines in FIG. 1 tothe positions shown in phantom, a link 35 is pushed forwardly (to theleft as viewed in FIG. 1) thereby swinging the arms 31 forwardly in anarcuate manner. The pins 32 press against the member 33 and cause theshaft 22 to move to the left, as viewed in FIG. 1. Since the movement oflevers 31 is arcuate, the pins 32 move slightly downwardly in the slotsbetween the members 33 and 34. When the shaft 22 is moved to the left asjust described, the projection 26 on the shaft 27 slides in the bore 25and is partially withdrawn therefrom.

As previously indicated, either of the wheels 10 and 20 may be thedriving wheel, the other then being the driven wheel. Let us assume, forpurposes of this description, that wheel 20 is the driving wheel. Itwill be seen that as the position of the wheel 20 is moved radiallyinwardly toward the center axis of wheel 10, with the axis of rotationof wheel 20 moving in the plane of the diameter of wheel 10, that thespeed at which the wheel 10 is driven will be increased. Thus, the speedat which wheel 10 and shaft 12 are driven is greater when drive wheel 20is in phantom position Pl than when it is in the position shown in solidlines.

If the drive wheel 20 is moved beyond the center axis of the drivenwheel 10, the direction of rotation of the driven wheel 10 is changed.Thus, when the drive wheel 20 is in the phantom position P2, the wheel10 is driven at the same speed as when the wheel 20 is in the positionshown in solid lines, but in the opposite direction. It will beunderstood that the illustration in FIG. 1 is simplified, and that, asthere shown, the lever arms 31 would be too short to achieve movement ofthe wheel 20 from the position shown in solid lines to phantom positionP2. This could be readily achieved, however, by increasing the lengthsof the lever arms, etc.

What has been said so far is known in the art. The present inventionresides in the construction of the circumferential edge of the wheel 20.In prior art mechanisms, the circumferential edge of the wheel 20frictionally engages the flat side surface of the wheel 10. Thus, whenthe position of the wheel 20 is changed relative to the wheel 10, thecircumferential edge of the wheel 20 is dragged frictionally across theside surface of the wheel 10, unless, of course, the two wheels aredisengaged before changing their relative positions.

In accordance with the present invention, the circumferential edge ofwheel 20 is provided with means which allow the circumferential edge ofwheel 20 to be rolled across the flat side surface of the wheel 10. Theside surface of wheel 10 may preferably be hard rubber or hard neoprene.

In the embodiment illustrated in the drawings, the circumferential edgeof the wheel 20 is provided with a series of circular discs, preferablysteel, each lying in a radial plane of wheel 20, and each having aportion projecting beyond the peripheral edge of the wheel 20. Theperipheral edges of the discs 40 are preferably half wound.

To receive the circular discs 40, the peripheral region of the wheel 20is provided with a series of radial slots 41 each having a widthcorresponding to, but slightly greater than, the thickness of the discs40, and each having a depth corresponding to approximately two-thirds tothree-quarters of the diameter of the discs 40. into these slots 41, thecircular discs 40 are placed.

To prevent the discs 40 from dropping out of the slots 41, whilenevertheless allowing the discs to move rotationally about their ownaxis, annular retaining bands 42 and 43 are placed on opposite surfacesof the wheel 20 and secured thereto as by bolts 44 which pass throughthe body 21 of the wheel between the slots 41. The inward surface ofeach of the retaining bands 42 and 43 is curved, as at 424 and 43a, in amanner corresponding to the curvature of the discs 40. The distancebetween the edge surfaces 42a and 43a is less than the diameter of thediscs 40 and thus the discs 40 are captive in the slots 41.

It will be seen from FIGS. 1 and 2, that when wheel 20 is drivenrotationally, by drive means not shown connected to shaft 27, theprojecting discs 40 engage successively the side face of the wheel andcause wheel 10 to move rotationally at a speed which is related to thedistance from the center axis of rotation of the wheel 10 to the pointof contact of the discs 40 with the side surface of the wheel 10. Whenwheel 20 is the driving wheel, the greater the distance from the centeraxis of rotation of wheel 10 to the point of contact by the discs 40,the slower the speed at which the wheel 10 is rotated. If, on the otherhand, the wheel 10 is the driving wheel and wheel 20 is the drivenwheel, then the speed of the driven wheel 20 increases as the distancefrom the center axis of the drive wheel 10 increases.

The particular means shown and described for mounting the rotatablesteel discs 40 about the circumferential edge of the wheel 20 is apresently preferred means. However, it is to be understood that it iswithin the spirit and concept of the present invention to use othermeans for mounting the discs at the circumferential edge of the wheelfor rotation about their individual axes.

With the construction shown and described, when the position of thewheel 20 is changed relative to that of the wheel l0,

d. a plurality of radial slots at the periphery of said one wheel;

e. a circular aide-less disc in each slot;

f. each slot having a depth greater than one-half but less than the fulldiameter of said circular disc, whereby a portion of each of said discsprojects beyond the periphery of said one wheel and is adapted to engagethe side surface of the other wheel;

g. each slot having a width corresponding to but slightly greater thanthe thickness of said circular disc to allow for rotation of said discin said slot;

h. retaining means for retaining said discs in said slots;

i. and means for moving the position of said one of said wheels alongits axis to change the positions of said wheels with respect to eachother while maintaining their right angle relationship.

2. A variable speed drive according to claim 1 characterized in that:

a. said disc-retaining means comprise annular retaining bands secured toopposite faces of said one wheel at the periphery thereof, saidretaining bands having surfaces curving inwardly to correspond to thecurvature of the edges of said discs.

1. A variable speed drive compriSing: a. a disc-like drive wheel; b. adisc-like driven wheel; c. means mounting said drive and driven wheelsfor rotation on axes disposed at right angles to each other and in suchposition that the circumferential edge of one wheel faces the sidesurface of the other; d. a plurality of radial slots at the periphery ofsaid one wheel; e. a circular axle-less disc in each slot; f. each slothaving a depth greater than one-half but less than the full diameter ofsaid circular disc, whereby a portion of each of said discs projectsbeyond the periphery of said one wheel and is adapted to engage the sidesurface of the other wheel; g. each slot having a width corresponding tobut slightly greater than the thickness of said circular disc to allowfor rotation of said disc in said slot; h. retaining means for retainingsaid discs in said slots; i. and means for moving the position of saidone of said wheels along its axis to change the positions of said wheelswith respect to each other while maintaining their right anglerelationship.
 2. A variable speed drive according to claim 1characterized in that: a. said disc-retaining means comprise annularretaining bands secured to opposite faces of said one wheel at theperiphery thereof, said retaining bands having surfaces curving inwardlyto correspond to the curvature of the edges of said discs.